Nosocomial infections and pseudoinfections from contaminated bronchoscopes: two-year follow up using molecular markers.

During a 6-month period, two genetically distinct clones were isolated from 65% of patients with Pseudomonas aeruginosa isolated from bronchial specimens obtained during or after bronchoscopy. This epidemic was due to contamination of bronchoscopes by washing machines. After reintroduction of manual disinfection of endoscopes, a significant decrease in the incidence of the epidemic clones was observed, but the incidence of nonepidemic P aeruginosa did not change. The distinction between sporadic and epidemic cases was possible only with the use of a molecular typing method (ribotyping).